What Factors Affect the Rate of Reaction Between Hydrochloric Acid and Calcium Carbonate?

Authors Avatar
What Factors Affect the Rate of Reaction

Between Hydrochloric Acid and Calcium

Carbonate?

Background knowledge

Many substances react when they come into contact with each other. To collide they

require kinetic energy. They require an excess of it to react; this is why reactions are more rapid

at greater temperatures. As the particles have more energy they are moving faster and are

therefore more likely to come into contact with each other.

Reactions between acids and alkalis as is the case here, will produce a neutralisation

reaction where the substance formed will be more neutral (closer to a pH 7) than the original

reactants. This is usually an exothermic reaction in which heat is given off due to the fact that

when the bonds of a new substance is formed there is excess energy.

The are many factors that can affect the rate of a reaction. These include temperature

which is explained in the first paragraph, surface area of a solid in a reaction, the concentration

of each substance, pressure, and quantities of each substance.

If the solid, in this case calcium carbonate, has a large surface area more acid molecules

can come into contact with it at the same time, allowing more to react simultaneously. If the

same volume of the solid is divided into smaller pieces it will have a greater relative surface area

The solid to the left is made up of 16 molecules, of which only 12 (red particles) are

exposed to any substance it may contact. The molecules on the right are the original solid

divided into smaller pieces. There are the same number of molecules but all of them are

exposed.

Another factor which will affect the rate of a reaction, is the concentration of the

substances, in this case hydrochloric acid. The acid solution being used is made from

concentrated hydrochloric acid, diluted with water and then halved continually with more water,

until the correct concentration is obtained.

The concentration of acid is measured in moles/litre

Mole =The atomic mass of the substance's formula in grams per 1000cc of solution, the rest

being water.

In this case we are using hydrochloric acid, it's formula is HCl

Hydrogen has an atomic mass of 1, and chlorine 35.5= 36.5

One mole (1M) =36.5g of hydrochloric acid in 1000cc of solution.

As the water molecules are very unreactive when added to calcium carbonate they will
Join now!


therefore restrict the amount of acid which can come into contact with and therefore react with

the calcium carbonate. The rate of reaction will be slowed more as the acid solution becomes

less concentrated.

A catalyst can be added to a reaction to accelerate it. It does this by holding the

reactants on is surface allowing them to react and decreasing the time they spend not in contact

and therefore not reacting with the other substance. Catalysts are used to accelerate many

industrial chemical reactions, such as ...

This is a preview of the whole essay